The concept of “probability” occupies a prominent place in the categorical apparatus of modern science, but a number of issues related to the clarification of the meaning of probability and the conditions of applicability of this concept have not been sufficiently investigated so far. Among them is the problem of the possibility of attributing probability to single events. Considering this question, we will deal only with the mathematical concept of probability and the logical interpretation based on this mathematical concept, leaving aside the philosophical aspect of probability, shown by the author in another work.